MEMS electrostatic actuators or transducers have a myriad of uses ranging from accelerometers to gyroscopes, to pressure sensors, microphones, etc. MEMS generally include components or elements that can be less than 1 μm to several millimeters, where at least some of the elements have some sort of mechanical functionality or aspect to them. For example, MEMS-based motion sensors for digital cameras has been developed to address the image degradation that results from human hand tremor or other blur-inducing actions, e.g., MEMS-based gyroscopes may be used to sense camera motion. In response to the sensed motion, an optical image stabilization (OIS) system attempts to move the lens or the image sensor to minimize or eliminate the resulting motion-induced blurring of the image, which can also be accomplished using MEMS-based actuators.
One example of a MEMS-based actuator relies on the use of a comb drive having at least two comb structures in an opposing orientation like interlocking teeth. Attractive electrostatic forces may be generated when a voltage is applied to the comb drive causing the comb structures to be drawn together, where those forces are proportional to the change in capacitance between the comb structures. Hence, such devices are traditionally voltage-controlled devices. Moreover, operation of comb drives can be based on the granularity or resolution provided, e.g., by a digital-to-analog converter (DAC). DACs are generally used to drive such devices because the associated electrostatic forces are nonlinear, and so appropriate digital values must be used to provide an appropriate amount of voltage to drive the devices.